A. J. Grove 
13 
arrangement of the tracheae in the thorax, but branches could be 
distinguished passing to the head and antennae much in the same way 
as in the apterous form. The stigmata, however, are clearly visible on 
the external surface and consist, as in the apterous stage, of two pairs of 
thoracic stigmata, and seven pairs of abdominal stigmata. The thoracic 
stigmata are situated, one pair in the prothorax and the other pair in 
the metathorax, and the abdominal ones occupy the first seven 
abdominal segments, one pair in each segment. An examination of 
transverse sections shows that, in the abdomen at any rate, each stigma 
opens into a single main trachea, which in this stage is more dilated 
than in the apterous form, and constitutes an air chamber, from which 
two main branches take their oi’igin, the one passing dorsally and the 
other ventrally, and presumably joining up with similar branches from 
other stigmata to make up a dorsal and ventral tracheal system as is 
present in the apterous form. 
Summary 
The Apterous Parthenogenetic Viviparous 
Female. 
External Characters. 
Segmentation indistinct. 
Hairs very numerous; six rows on the 
thorax and abdomen ; capitate. 
No black pigment. 
The Alimentary Canal. 
The coiled intestine describes two back¬ 
ward coils and one forward coil. The first 
backward coil occurs immediately after 
leaving the crop; then, after forming the 
forward coil, which occurs at the posterior 
end of the body, the intestine again reaches 
the region of the crop where the second 
backward coil occurs just before the com¬ 
mencement of the rectum. All the coils 
are in a horizontal direction. 
The Winged Parthenogenetic Viviparous 
Female. 
External Characters. 
Segmentation more distinct, mesothorax 
much enlarged. 
Hairs less numerous ; only two rows on 
the abdomen; capitate. 
Many patches of black pigment on the 
body. 
Wide separation of the first and second 
pairs of legs. 
The Wing Muscles. 
A single elevator and depressor muscle 
for each wing, and a set of eight longi¬ 
tudinal muscles which assist in depressing 
the wings. 
The Alimentary Canal. 
The first backward coil is completely 
absent, and where the second backward coil 
should occur, there is a complicated coil 
consisting of first a vertical coil on the 
right hand side of the crop then a horizon¬ 
tal coil passing beneath the crop followed 
by another vertical coil just before the coiled 
intestine gives place to the rectum. 
